Electronic systems and devices have made a significant contribution towards the advancement of modern society and have facilitated increased productivity and reduced costs in analyzing and communicating information in a variety of business, science, education, and entertainment applications. These electronic systems and devices are typically tested to ensure proper operation. While testing of the systems and devices has made some advances, traditional approaches are typically expensive and often have limitations with regards to throughput and convenience.
FIG. 1 is a block diagram of an exemplary conventional testing approach. It consists of a large controlled environmental chamber or oven 71 that contains an oven rack 10 and heating and cooling elements 11. The oven rack 10 contains devices under test (DUTs) in a number of loadboard trays 31, 32, 33, 34, 41, 42, 43, and 44. The environmental test chamber 71 has solid walls and a solid door 72 that enclose the test rack 10. The heating and cooling elements 11 can have a wide temperature range (e.g., −10 to 120 degrees C.). The test head 81 contains various racked components, including system controller network switches 52, system power supply components 53 and tester slices 50 (the tester slice contains the tester electronics). The loadboard trays 30 are loaded with devices under test and connected to tester slices 50 (multiple loadboard trays can be coupled to a single tester slice).
Conventional systems are not typically well suited for convenient testing because: 1) they are large systems that are stationary; 2) expensive to build, maintain and operate; and 3) are usually single purpose with limited flexibility. The components of traditional systems are typically tightly coupled and highly dependent upon each other for proper testing (e.g., tight speed clock requirements, hard wired high power cables, various close synchronization requirements, etc.). The large size and numerous hard wired components typically prevents mobility of the system to convenient testing locations. It is usually difficult to make changes in conventional single or limited purpose test systems (e.g., to meet or stay up with: advances in DUT technology, new or amended test protocols, DUT market demands, etc.). Changes in systems that have tightly coupled components usually involve numerous extensive and costly impacts to the whole system, and even if the change is only to a portion, the entire conventional tester system (e.g., test head, oven, etc.) typically needs to be shut down.
Traditional test approaches do not typically allow flexible or continued testing of some DUTs while other changes in other DUTs or test protocols are made. Furthermore, testing issues that arise during testing in a small portion of the large overall system can cause adverse impacts and delays throughout the whole system. There is a long felt need for a convenient and flexible volume production electronic device testing approach.